Sprinkler



Oct. 20, 1959 J. o. HRUBY, JR

SPRINKLER Filed Jan. 24, 1958 0 1 4 w a 4 A 5 a 5 2 fi M a 1 ,QJ a ZI Q I I m a L. f w 3 v A z 4 1 1 4 v @MM Km. WWW H N m w 147' raezvsys.

United States Patent 2,909,326 SPRINKLER John 0. Hruby, Jr., Burbank, -Calif., assignor, by mesne assignments, to Rain Jet Corporation, Burbank, Calif.

Application January 24, 1958, Serial No. 710,989 g 6 Claims. 01. 239-206) This invention relates to fluid discharging devices which are especially well suited for employment as lawn sprinklers. The fluid discharging devices of this invention are similar in certain structural features thereof to the sprinklers illustrated and described in my copending appli cation for Letters Patent, Serial No. 660,00Q, filed May 17, 1957.

The sprinklers of said copendingapplication are characterized by a tubular stem disposed longitudinally in a sprinkler body and arranged to be rotated on the stem axis and gyrated in the body withthe axis of the stem being inclined with respect to the axis of the body thereby to cause streams of water from orifices in the upper end of the stem to swing upwardly and downwardly as they rotate, with the result that the water is distributed over a wide area around the sprinkler.

The sprinklers of said copending application differ from those illustrated and described in letters patent of the United States No. 2,639,191, issued to me on May 19, 1953, by locating the inlet opening of the stem within the sprinkler body. As explained in said copending applica* tion, a sprinkler of such construction produces a spray of Water over a large area of lawn but at a relatively low rate of water discharge, i.e. lowgallonage (gal./rnin./sq. ft.), thus to permit spraying over a large area for a long period of time without surface water run-off.

In the low gallonage sprinklers of saidcopending ap- "I 26 Patented Oct. 20, 1959 Fig. 1 is a central vertical section through a sprinkler embodying the invention;

Fig. 2 is a side elevation of the body portion of the sprinkler, with the stem of the sprinkler in raised position in the body;

Fig. 3 is a plan view, on a reduced scale, of the stem and body shown in Fig. 2; and

Fig. 4 is a transverse section through the sprinkler takenon line 4-4 of Fig. 1.

Referring tothe drawing in detail, a sprinkler embodying the invention is shown and designated generally by numeral 10. The sprinkler is secured on the top of a riser pipe 11 which is connected at its lower end to a supply pipe (not shown) of a sprinkler system.

The sprinkler 10 includes a hollow body comprising a tube 14 and a cap 15 into which the tube is screwthreaded as at 16. The inside walls of the tube 14, defining the bore of the tube, are designated by numeral 17. Extending into the upper end portion 17 of the bore of the tube is a bearing sleeve 18 having a flange 19 projecting radially outwardly from the upper end of the sleeve thus to permit engagement of the flange. between the upper edge of the tube and the inside surface of the cap for securing the sleeve in the upper end of the sprinkler body. The cap has a centrally disposed opening ll formed therein, said opening being slightly larger in diameter than the bore 22 of the sleeve 18.

Arranged longitudinally in the sprinkler body is a tubular stem 25 which extends upwardly through the bore 22 of the bearing sleeve 18 and through the opening 21 of the cap. The bore 22 of the bearing sleeve is slightly larger in diameter than the outside diameter of the stem to permit inclination of the stem in the bore 22 as will be explained more fully hereinafter. Numeral 26 designates the axially extending passage or bore of the stem,

' the same being open at its lower end 26 as an inlet plication, slits extending longitudinally of the body are 7 formed in the body side walls and suchslits extend through the body side walls at an angle to the radii of the body, thus to cause the water from the slits to im' part a swirl to the water in the body.

I have now found, according to the instant invention, that spinklers of the low gallonage type will function efliciently and effectively in constructions where the slits referred to above are not disposed at an angle to the radii of the sprinkler body. slits as such, either slanted or radially aligned, are needed and that the sprinkler body may in effect be entirely open to the flow of water, and still the stem will gyrate in the body and rotate on its axis, solong as a cup is so located with respect to the lower end of the stem to limit and confine rotation of the lower end of the stem Within the cup.

It will be apparent that elimination of slanted slits or other angled openings in the sprinkler body will permit manufacture of low gallonage sprinklers of the above I In fact, I have found that no opening 27. Y

There is a head 29 arranged as a collar around the upper end of the stem. Its under surface 30 is conical. The stem is movable longitudinally in the sprinkler body and it is moved upwardly to the position thereof shown in Fig. 1 of the drawing, by the force of water flowing through the sprinkler. When the water to the sprinkler is turned off, the stem drops down into the body until the head 29 seats on the bevelled rim 31 around the opening 21 of the cap.

A collar 33 is fixed as by set screw 34 around the stern. Upward movement of the stem in the body is limited by abutment of the upper end shoulder 35 of the collar against the lower end of the bearing sleeve 18, thus to retainthe stem in the body and still permit rotation or the stem on its longitudinal axis.

The head 29 has preferably a plurality of orifices 36 formed therein. and these are spaced around the head and extend radially outwardly and are inclined upwardly from the stem. There are four such orifices in the illustrated embodiment and these are aligned with respective openings 37 in the stem whereby water in the stern will pass out throughthe orifices 36 in streams extending radially outwardly from the sprinkler. The stem bore is closed at its upper endby a plug or ball 38 which is force-fitted inthe stem.

The sprinkler 10 is designed to cause the water passing through it to impart gyration to the stem, such that the upper and lower ends of the stem revolve in respective circles with the stern being inclined with respect to the axis of the sprinkler'body. It appears that the stem in being so gyrated follows or describes the outside surface of that certain three dimensional graph known as a hyperboloid' of one sheet. That portion of the stem which is disposed within the bearing sleeve 18 when the 3 stem is in its upwardly disposed position, traces the smallest circle of such hyperboloid of one sheet.

To prevent the stem from becoming inclined in the bore 22 of the bearing sleeve 18 to such an extent that it will be pressed tightly against both of the end rims of the bore and as a result stop its gyratory motion, the sprinkler is provided with a cylindrical bearing sleeve 41 disposed around the lower or inlet end of the stem, whereby the inside wall of the sleeve 41 limits the size of the circle described by the lower end of the stem and thus prevents canting of the stern tightly against the upper sleeve 18.

Engagement of the stem along the inside surfaces of the bearing sleeves 18 and 41 causes the stem in its gyratory motion as described above, to roll on said surfaces with the result that the stern rotates on its axis in addition to gyrating in the sprinkler body. Such rotation of the stem on its axis causes the streams of water from the orifices 36 to travel around the sprinkler. The gyratory movement of the stem in its inclined relationship provides for upward and downward movement of the streams of water, i.e. at a given point in the rotation of the stern one of the streams of water is directed outwardly to fall on the periphery of the area being sprayed, and as rotation of the stem is continued that stream is directed to fall inwardly of the periphery, each of the other streams likewise alternating in their action of moving outwardly toward and then inwardly from the periphery of the area being sprayed, thereby to evenly distribute the spray over a wide area around the sprinkler.

The sleeves 18 and 41 are preferably formed of wear resistant laminated phenolic composition to increase the life of the sprinkler.

A plate 43 extends over the lower end of the sleeve 41 thus forming a cup 44 into which the lower end of the stem extends. In the illustrated embodiment the cup is maintained in position to contain the lower end of the stem, by forming the tube 14 of suificient length to receive the sleeve 41 and to accommodate the end plate 43, the sleeve and plate being force-fitted or otherwise suitably secured in the lower end of the tube. The side walls of the tube are cut away substantially to form large openings 45, leaving narrow strips 46 (herein two strips) which serve to suspend the cup 44 from the upper part of the sprinkler body.

The cup 44 is of sufiicient depth to allow the stem to drop down in the sprinkler body to a position where the stem head 29 seats upon the cap 15, and the sleeve 41 extends upwardly beyond that level reached by the lower end of the stem where the stem is in its upwardly disposed, or pop-up position.

Having supposed heretofore that slant openings were needed in the sprinkler body in order to impart a swirl to the water in the body, thus to gyrate the stem in the body, I do not now intend to set forth as a theory an explanation of the nature of the forces of water which cause gyration of the stern in the fluid discharge device of this invention; however, by way of suggestion, it appears that inasmuch as the rim of the cup 44 (such rim being designated by numeral 48) is disposed above the Water inlet end of the stern, the downward flow of water into the cup from over the cup rim and the change in direction of flow to upwardly into the stern, may cause gyration of the stern. But whatever may be the theory for properly explaining the forces which cause gyration of the stem, the stern does in fact gyrate around in the body. It may at one time gyrate in a clockwise direction and then for the next time that water is turned onto the sprinkler, the stem may gyrate in a counterclockwise direction.

The above suggestion that the change in direction of flow of fluid in the cup causes gyration of the stern, appears to be substantiated by the fact that a small opening may be made in the bottom (plate 43) of the cup and still the stem will gyrate, but when such opening is the stem, gyration of the stern will not result. I have concluded that such small opening in the bottom of the cup merely supplies an auxiliary volume of water which if large enough will nulify the effect of fluid flowing downwardly in the cup and thence up into the stem.

The fluid discharging device of this invention is designed as a lawn sprinkler by providing a casting into which the sprinkler body is disposed. For connecting the body to the casting, the cap 15 of the body is screwthreaded as shown at 51 into an axial opening 52 in the casting. A central recess 53 is formed in the casting and this recess serves to receive the stem head when the stem drops down in the sprinkler body to its stand-by position, thereby to protect the stem from damage by traffic over the lawn. The casting has a skirt portion 54 and screw threads 55 formed in the inside wall of the skirt portion whereby the casting may be secured on the upper end of the riser 11. i

Because the sprinklerbody of this invention is in effect entirely open to the flow of water from the riser, the cup 44 apparently serving only to cause change of direction of flow of water before entering the stem, the space between the cup and the upper portion of the body may' easily be covered by an effective filter without impairing the gyrational and rotational operations of the stem. I have found, according to this invention, that a sheet having narrow slits formed therein serves most effectively in filtering out sand and other particles which may be carried by the water in a sprinkler installation. Thus I provide a sheet having parallel slits 61 formed therein, the sheet 60 being formed into a cylinder with the side edges of the sheet being overlapped, and with the slits extending longitudinally of the cylinder, whereby the cylinder may be telescopically received over the tube 14 of the sprinkler body. In the illustrated embodiment the filter cylinder has rings 62 and 63 on the inside of respective ends thereof. These rings fit tightly around the tube 14 and its cup 44 respectively.

While the instant invention has been shown and described herein, in what is conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope of the invention, which is therefore not to be limited to the details disclosed herein, but is to be accorded the full scope of the claims.

*What I claim is:

1. A fluid discharging device adapted to be mounted in a fluid supply pipe and comprising a cap having an opening extending therethrough, means for securing the cap upon the pipe, a tubular stern extending through said cap opening and having an inner end and an outer end, the outer end of the stern having a fluid outlet orifice, the inner end of the stem having a fluid inlet opening, the stem being rotatable on its axis, stop means on the stern for maintaining the stem against outward removal through said cap opening, a cup spaced from said cap, the cup having a rim defining the cup opening, the inner end of the stern being disposed in said cup, the device being open to the flow of fluid from said supply pipe into said cup over the rim of the cup whereby fluid will flow into the cup and thence through the stem thereby to gyrate the stem with the inner end of the stem contacting the inside wall of the cup to roll on the inside wall of the cup and impart rotation to the stem on the stem axis.

2. A fluid discharging device according to claim 1 and having a sheet over the open space between said cup and said cap, said sheet having small openings formed therein for filtering solid particles from fluid entering said device.

3. A fluid discharging device according to claim 1 in which said sheet is formed into a cylinder telescoped over said cup, and said filter openings in the sheet constitute a narrow slit.

4. A lawn sprinkler adapted to be mounted in a riser of a lawn sprinkler system and comprising a cap having an upper surface and a lower surface and an opening extending therethrough, means for securing the cap atop the riser, a tubular stem extending through the cap opening, the stem having an upper end and a lower end and an outlet orifice formed in the upper end portion thereof and an inlet opening formed in the lower end portion thereof, the stem being movable longitudinally in the cap opening and being rotatable on its axis, stop means on the stern for limiting upward movement of the stem in the cap opening, a cup, the lower end of the stem being disposed in the cup and engageable along a circle around the inside wall of the cup, means supporting the cup spaced below the cap, the cup having a rim defining the upper limit of the side walls of the cup, said rim being disposed above said circle, and the inside diameter of the cup being larger than that of said cap opening, whereby water flowing into the cup over the rim thereof will cause the stem to gyrate with its axis inclined with respect to the axis of the cap opening and the axis of the cup, the surface of the three dimensional graph described by the stem in its gyratory motion being generally a hyperboloid of one sheet.

5. The sprinkler of claim 4 including a collar around the upper end of the stem for preventing the upper end of the stem from dropping below the upper surface of the cap. 7

6. A lawn sprinkler comprising a cap having an upper surface and a lower surface and an opening of circular cross section extending axially therethrough, a flanged casting for securing the cap atop a riser of a lawn sprinkler installation, the cap having a cylindrical skirt extending downwardly from said lower surface of the cap and in axial alignment with said cap opening, an elongate body having cylindrical side walls and an upper end and a lower end and an axially extending bore formed therein, the upper end of the body being secured in said skirt, a bearing sleeve secured in the upper end of the body, said sleeve having a bore extending axially therethrough in axial alignment with the cap opening, a tubular stem extending into the bore body through the cap opening and through the bore of the bearing sleeve, the stem having an upper end and a lower end and an outlet orifice in the upper end and an inlet opening in the lower end, the stem being movable longitudinally in the body bore and rotatable on its axis, stop means on the stem for limiting upward movement of the stem in the 1 body bore, means substantially closing the lower end of References Cited in the file of this patent UNITED STATES PATENTS 2,595,598 Morton May 6, 1952 2,639,191 Hruby May 19, 1953 2,723,879 Martin Nov. 15, 1955 2,823,952 Hruby Feb. 18, 1958 

